Am I expecting too much from error 404 page ???

I've a 404 error page configured to send me an email when a page is not found. However I was expecting the page the user typed in to be displayed in the email, so I could verify if this is a valid page or not.

E.G. User types in www.domain.com/xrz.html so in the email it tells me the domain typed was www.domain.com/xrz.html, but the code just tells me www.domain.com/404.html

my code is:

<?php
$count = 0;
// don't send mail if we don't know the referring page
// it's probably a searchengine or infected windows system requesting known NT server exploits
// may reinstate but wana know if works
//if ($HTTP_REFERER == "")
//{
//$count++;
//}
// debug comment, you can remove this line if you want:
echo "<!-- count: $count -->\n";
if ($count == 0)
{
$today = date("j F Y, G:i:s");
$message = "Date and Time: $today\nRequest URL: http://$SERVER_NAME$REQUEST_URI\nReferring page: $HTTP_REFERER\n\nClient: $HTTP_USER_AGENT\nRemote IP: $REMOTE_ADDR\n\n";
$message .= "This is an automated message.\n\nIan.";
mail("email@domain.com", "Error 404", $message, "From: email@domain.com\nReply-To: email@domain.com");
}
?>

PHP:

This is my .htaccess file:
ErrorDocument 404 http://www.domain.com/404.html

AddType application/x-httpd-php .php .htm .html

Thanks for any pointers.

Ian

 

15. $message = "Date and Time: $today\nRequest URL: http://$SERVER_NAME$REQUEST_URI\nReferring page: $HTTP_REFERER\n\nClient: $HTTP_USER_AGENT\nRemote IP: $REMOTE_ADDR\n\n";

Use $_SERVER['HTTP_REFERER'] instead of $HTTP_REFERER, the same goes for the rest of the variables on line 15